Daily News

More than 1000 second lactation or greater lactating dairy cattle were enrolled in a trial to determine the effect of hyperimmunization (HI) on severe clinical mastitis. Cows in the control group were immunized with three doses of J5 bacterin; cows in the HI group received and additional three doses of J5 during the first three months of lactation. Although the incidence of clinical mastitis did not differ between groups, HI cows were less likely to have severe clinical mastitis and were less likely to leave the herd before day 305.